Brazilian defender Luiz was used as a substitute in Wednesday's 0-0 draw at Swansea, but ended the game limping and is now a doubt for next week’s Premier League game at Reading.

However, Benitez did reveal that former England defender Terry has returned to training and has a good chance of playing in the fourth-round tie.

“At the moment we have David Luiz who will not be available,” Benitez told reporters. “He won't be fit for this game and it will be difficult for him to be ready for Reading.

“Terry has been training again so he is fine, maybe he will have a chance. He was doing really well in the training sessions and was on the bench just in case we needed him at the end. He is doing well, progressing and will have a chance to play.”

Benitez also insisted he is aware of the threat the League One minnows will pose to the European champions on Sunday.

He said: “It will be a tough game, it's a massive game for them and they will be pushing, playing between long and short passes and they try to win second balls. They're an interesting team and doing well.

“I have seen some clips and have some notes. I have seen some games and was talking with the scouts so we know they are doing well.

“Obviously we play away, and it's a cup competition. It will be different and our approach has to be different. The pitch is not the best, totally different, but it's a game we play against a close team which will be a massive motivation for them too.”

Although the Spaniard conceded his players are disappointed at being knocked out of the Capital One Cup, he is relishing the chance to immediately put that right.

He continued: “Everybody is really disappointed because we thought we could be there, scoring goals, not conceding goals.

“We were doing the right things, even in the first game against Swansea we were on top and creating chances, so everyone is disappointed because it's an opportunity we have lost,' he said.

“They are professionals and know we have a difficult situation with a game each three days. It's good when you lose because you have another game in three days. Now we have another competition, another challenge and we can move forward quickly.”